if you want to play respawn join The Fallen Ones Anti-DDOS Respawn Server, i made the respawn mod used there, it is a little buggy but it is fun, i am working on a new version trying to eliminate the bugs.
once in a while when you respawn your spectating yourself all you have to do is leave and come back if that happens.
as far as adding it to assist goes not sure if they would add it as an official assist mod, but respawn can be played whether assist adds it or not.
i released my RespawnMod and the source code for it here:
https://aao25.com/forum/games-programming/respawnmod-(servermod)/the download link is no longer vaild i will have to update it at some point but noone seemed interested enough to download it and put it on their servers.
as a matter of fact even my ultimatemod the worked really well in my opinion people didnt really seem interested in, ive had one person pm asking how to put it in their server and i told them, never heard anymore about it, and shady from the nexus clan had me put it in the nexus pickaweapon server as you could pick your own guns in this mod, other then that ive really been the only one using these 2 mods.
Both mods were released publicly on this website.
if you have your own server and would like the respawnmod on it pm me and ill get the mod uploaded and produce a link to downloaded from.